1. Field of the Invention
The invention relates to a damper for mounting between a power tool having an axis of vibration, on the one hand, and a handle device for the power tool, on the other hand, wherein the damper comprises a damping means for damping impacts (absorbing shocks) and a distancing means. The invention further relates to a handle for a power tool having an axis of vibration and to a power tool having an axis of vibration, in particular a drill or impact drill or a hammer drill.
2. Description of the Related Art
Hand-operated machine tools such as power tools, for example angle grinders or power cutters (cut-off-saw), polishing machines, drills, hammer drills or the like comprise a main handle formed on or fixed to a motor housing or the like. The machine tool is held and guided at the main handle. Additionally, it may be useful to provide an additional handle for the other hand of the user. Such an additional handle is usually releasably fixed to the transmission housing of the machine tool, for example. Configured as fixed stock handle it protrudes radially with respect to the longitudinal axis of the machine tool and facilitates guiding in difficult processing tasks.
Vibrations created due to operation propagate from the machine tool via the additional handle, in particular, to the hand or the arm of the user. In order to reduce the level of vibrations acting upon the user, known stock or additional handles having elastic damping elements are provided. An example for an additional handle known from the prior art for reducing the level of vibrations acting upon the user is described in EP 1 867 443 A1.
The vibrations of the power tool, for example a drill, impact drill or hammer drill, are generated along an axis of vibration. In the case of a hammer drill, the axis of vibration denotes for example the axis along which a chiseling tool or the like will impact onto the substrate to be processed. The shocks and vibrations generated here are transmitted both directly via the tool housing and the main handle formed thereon and via the additional handle to the hands or arms of the user. Due to the partly enormous shocks and vibrations arising when using a corresponding power tool, these represent high stresses, especially onto the joints of the user. A damping of these vibrations is absolutely necessary, in particular for the purposes of occupational health so as to effectively avoid permanent damages to health resulting from the use of such a power tool.
The damping effect of the damping elements known from the prior art is, however, not optimal. A handle part and a damping element that are connected to the machine tool by an attachment part are provided. In additional handles of the state of the art, the arrangement of the damping element is provided, in different configurations, in a handle part or as a connection between a handle part and an attachment part. Moreover, in the state of the art, a tear-off protection is generally recognized as necessary, too, so that upon damage of the damping element a tearing-off of the handle part can be prevented. The tear-off protections described in the prior art are, however, complex and expensive.
GB 2 376 913 A describes a damper for an additional handle of a hand-held tool. The damper contains a support guiding the handle in a direction of motion and limiting the relative motion between the handle and the tool. One or more springs damp impacts in the direction of motion.
Overall, the damping effect of the additional handle having elastic damping elements as described in the state of the art is not satisfactory.